Unable to charge the headphone amplifier. (PHA-1A, PHA-2A, PHA-3)

Rotate the Power/volume knob counterclockwise until it clicks to turn off the Headphone Amplifier.

*The following picture and diagram are the example of PHA-2A.

NOTE: The CHG POWER indicator lights up in red while the battery is being charged. It turns off when charging is completed.

*The following diagram is the example of PHA-2A.

When charging the headphone amplifier via an AC outlet, connect the supplied micro-USB cable for charging to the DC IN 5V/CHARGE port of the headphone amplifier.

NOTE: Use the supplied micro-USB cable for charging the headphone amplifier. Charging may fail if you use other cables.

*The following diagram is the example of PHA-2A.

Charge the battery in a location with an ambient temperature between 5 °C to 35 °C.When the ambient temperature is low or high, the headphone amplifier may not be charged.

When the headphone amplifier has not been used for a long time, it may take a while for the CHG POWER indicator to light up in red. In this case, do not disconnect the micro-USB cable from the headphone amplifier. Wait until the CHG POWER indicator lights up in red.

When you charge the headphone amplifier via a computer, take notice of the following.

Use the supplied micro-USB cable for charging the headphone amplifier. Charging may fail if you use other cables.

Check that the headphone amplifier is directly connected to a computer using the micro-USB cable (supplied). Charging may not be completed properly by an indirect connection, such as via a USB hub.

Turn on the computer first, then charge the headphone amplifier.If the computer enters standby mode (sleep mode) or hibernate mode, the headphone amplifier may not be charged. Make sure that the computer is turned on.

When the measures above do not solve the problem and there are other USB ports on your computer, connect the headphone amplifier to another USB port.If the headphone amplifier starts to be charged, the UBS ports on the computer may have a problem.